Experimental Results of Network-Assisted Interference Suppression Scheme Using Adaptive Beam-Tilt Switching

Abstract

This paper introduces a network-assisted interference suppression scheme using beam-tilt switching per frame for wireless local area network systems and its effectiveness in an actual indoor environment. In the proposed scheme, two access points simultaneously transmit to their own desired station by adjusting angle of beam-tilt including transmit power assisted from network server for the improvement of system throughput. In the conventional researches, it is widely known that beam-tilt is effective for ICI suppression in the outdoor scenario. However, the indoor effectiveness of beam-tilt for ICI suppression has not yet been indicated from the experimental evaluation. Thus, this paper indicates the effectiveness of the proposed scheme by analyzing multiple-input multiple-output channel matrices from experimental measurements in an office environment. The experimental results clearly show that the proposed scheme offers higher system throughput than the conventional scheme using just transmit power control.

Interference Management by Vertical Beam Control Combined with Coordinated Pilot Assignment and Power Allocation in 3D Massive MIMO Systems

“…where denotes the weight vector of antennas for the near sector. Same as the work [14], the influence of antenna weights on the transmission is included into the beam pattern by Eq. (1).…”

“…Considering the complexity and difficulty of the above optimization problem, particle swarm optimization (PSO) optimization algorithm is applied. The details of resolving problem (13) based on PSO algorithm are similar to the problem (14) in Section 4, which can be referred to Part 2 in Section 4.…”

“…This traditional algorithm calls for unacceptable complexity. In order to efficiently solve the joint adaptation problem in (14), some suboptimal approaches such as particle swarm optimization (PSO) optimization algorithm in [15] can be applied. The PSO based optimization algorithm for problem ( 14) is described as the following procedure:…”